Coal stoker



Oct. 30, 1934. v. c. NORQUIST COAL STOKER Filed June 10, 1932 V/ BY Jim fiJW A TT ORNE Y.

Patented Oct. 30, 1934 UNITED STATES PATENT OFFICE COAL STOKER Application June 10, 1932, Serial No. 616,426

2 Claims.

My invention relates to a coal stoker, and more particularly to a novel coal hopper arrangement for an automatic coal stoker.

In existing automatic stokers, coal is placed in a hopper from which it is fed by means of a conveyor through a coal duct to the grates in which it is to be burned. A long coal duct is a distinct disadvantage inasmuch as it requires more power to turn a long conveyor screw and due to the fact that a long conveyor screw will tend to twist due to the torsional stresses involved. The hopper is, therefore, placed fairly close to the furnace and in this position it will restrict access to the furnace doors for purposes of removing clinkers, inspecting the fire, making repairs and the like. In order to hold the requisite amount of coal, it is usually necessary to provide for a stoker hopper of some size, making the height of the hopper fairly large, making it more or less diflicult to put the coal therein. If the coal is wet or damp it has a tendency to pack, which results in arching over the feed screw. This arching may take place to an extent sufiicient to prevent feeding of coal to the fire.

One object of my invention is to provide a novel hopper arrangement which will overcome the disadvantages pointed out above.

Another object of my invention is to provide a coal feeding arrangement which will admit of the employment of a long and lower hopper in a position which will give ready accessto the furnace door for the removal of clinkers.

A further object of my invention is to provide a coal hopper of such dimensions as will preventarching of the coal in the hopper.

Other objects of my invention will appear from the following description.

In the accompanying drawing in which like reference nuerals are used to indicate like parts in the various views and which form parts of the instant specification and is to be read in conjunction therewith:

Fig. 1 is a plan view of a stoker equipped with a coal feeding arrangement embodying one method of carrying out my invention.

Fig. 2 is a sectional view taken on the line 2-2, Fig. 1.

Fig. 3 is a fragmentary sectional view taken on the line 33, Fig. 2.

Fig. 4 is a sectional view taken on the line 44, Fig. 2.

In general, my invention contemplates providing an elongated coal hopper of less height than is the usual practice, extending at right angles to the coal duct in a direction which will not obstruct the furnace front. I provide a coal feeding screw extending longitudinally of my hopper- Keyed to this screw is a gear wheel adapted to act as a worm wheel in connection with the main coal feeding screw which will act as a worm to actuate the worm wheel. The coal feeding screw will extend at right angles to the hopper screw. The length of the hopper is such that arching is overcome. The height of the hopper makes it an easy matter to place coal therein. The hopper may, furthermore, be made of any desired capacity, and may extend to a filling opening on'the exterior of a dwelling house so that the coal may be dumped directly into the hopper.

More particularly, referring now to the drawing, a motor 1 drives the blower which is encased in blower casing 2, and drives the transmission 3 to rotate coal feeding screw 4. A hopper 5 extends at right angles to the coal feeding screw 4 and is provided with a con eyor screw 6 which is mounted in the hopper in suitable bearings 7 and 8. A coal duct 9 leads from the hopper 5 to the combustion pot 10 and houses the coal feeding screw 4. Air from the blower 2 passes through air duct 11 to the combustion pot 10.

Keyed to the shaft 12 of the hopper screw 6, is agear wheel 13 having angularly disposed teeth 14 integral therewith. The teeth 14 engage the coal feeding screw 4 as can readily be seen by reference to Fig. 3. As the transmission 3 rotates the coal feeding screw 4, the gear wheel 13 will rotate to operate hopper screw 6 to feed coal from thehopper to the coal duct 9, which is cut away in the region of the hopper as can be seen by reference to Fig. 2. The pocket-like portion 15 which is virtually an extension of the coal duct is formed in the base of the hopper and houses the coal feeding screw 4. Coal is picked up by the coal feeding screw 4 and fed through duct 9 to the combustion pot 10, where combustion takes place in the usual manner common to underfeed stokers.

It is believed that the operation will be obvious from the above description. It will be noted that I have accomplished the objects of my invention. I am enabled in a simple, expeditious, and

economical manner to utilize a coal duct which willnclear the furnace door and of such shape as to prevent the occurring of arching. Likewise, I am enabled to utilize a coal hopper of any desired capacity without obstructing the furnace. Due to the low height of the coal hopper it is easily filled when shoveling coal therein from a coal bin.

It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of my claims. It is further obvious that various changes may be made in details within the scope of my claims without departing from the spirit of my invention. It is, therefore, to be understood thatmy invention is not to be limited to the specific details shown and described.

Having thus described my invention, what I claim is:

1 An automatic stoker comprising in combination a combustion pot, a coal hopper, a coal duct establishing communication therebetween, a conveyor screw positioned in said duct and having a part thereof extending into said hopper, whereby it is adapted to convey coal from the hopper to said combustion pot through said coal duct, a conveyor screw positioned within said hopper and extending in a direction intersecting the direction of the axis of said firstconveyonscrew, a gear wheel mounted on said second screw having angularly disposed teeth engaging said first named screw, the construction being such that said second screw will be actuated by said first screw to move coal along said hopper toward said first screw.

2. An automatic stoker comprising in combination a combustion pot, a coal hopper, a coal duct establishing communication therebetween, a first coal conveying means positioned in said duct and having a portion thereof extending into said hopper whereby it is adapted to convey coal from the hopper to said combustion pot through said coal duct, a second coal conveying means positioned within said hopper and extending in a direction intersecting the direction of the axis of said first conveying means for moving coal toward said first conveying means, interengaging means operatively connecting said first and second coal conveying means, the construction being such that said second conveying means will be actuated from said first conveying means through said interengagingmeans to move coal along said hopper toward said first conveying means.

' VICTOR C. NORQUIST. 

